Abstract: According to single factor experiments,using response surface optimized the process of extraction oil from black sesame dregs by subcritical CO_2. The optimum conditions were follows: extraction pressure 15 MPa,extraction temperature32 ℃,CO_2 flow 48 L / h,and the yield could reach 11.18%.The regression equation was fitted well.The fatty acids and bioactive products in sesame oil extracted by subcritical CO_2 and commercially available were both tested by Gas chromatography- mass spectrometry( GC- MS) and the main components were oleic acid,palmitic,stearic acid and linoleic acid. Furthermore,sesame oil extracted by subcritical CO_2 showed a good quality with clear,transparent,and sesame aroma after testing indexes of physical and chemical. This test may provide a theoretical basis for extraction of sesame oil from sesame dregs by subcritical CO_2.